Phonograph



1933- -H. F. M. GRAMAN'N PHONOGRAPH Fild June 16, 1953 Q Sheets-Sheet 1E MAX GRAMAAW Gttomeg Aug. 23, 1938.

H. F. M. GRAMANN PHONOGRAP H Filed June 16, 1933 HEINRICH EMAx GRAMANN(Ittomeg Aug. 23, 1938. H. F. M. GRAMANN PHONOGRAPH Filed June 16, 19333 Sheets-Sheet 5 Heme/cu l2" MAX GRAMA NN (Ittomeg Patented Aug. 23,1938 UNITED STATES PHONOGRAPH Heinrich F. Max Gramann, Orange, N. J.,as-

signor to Thomas A. Edison, Incorporated,

West Orange, Jersey N. .L, a corporation of New Application June 16,1933, Serial No. 676,037

2 Claims.

This invention relates to phonographs and more particularly tophonographs of the business or commercial type, which are adapted torecord as well as to reproduce dictation. This invention is especiallydirected to a novel and improved construction for back-spacing the armor carriage which carries the recording and reproducing mechanism so asto cause repetition of any portion of the record whenever the operatorof the machine so desires.

Phonographs designed for both recording and reproducing dictation arenow generally so constructed and arranged that the carriage for therecording and reproducing mechanism may at any time be manually moved orspaced back with respect to the record tablet, so .as to reproducepreviously recorded matter on said tablet. When a dictator, using such aphonograph for recording dictation, desires to reproduce previouslydictated matter, it is necessary-first, to manually readjust therecording and reproducing mechanism to neutral position; second, to movethe carriage backwardly along the record tablet a distance dependingupon the amount of matter to be reproduced; and third, to set therecording and reproducing mechanism in reproducing position. Theapparatus is then in condition for reproducing and the dictator maylisten to the recorded matter. When the reproduction of such matter hasbeen completed and it is desired to dictate further, it is necessary forthe dictator to again manipulate the recording and reproducing mechanismto return it to the recording position. Such manipulations incident to arepeating operation in the normal use of dictating machines aredistracting in addition to requiring considerable of the dictators time.Dictators may often neglect to' recondition the recording andreproducing mechanism for recording after completing reproduction and inconsequence they proceed to dictate while the reproducing stylus remainsin engagement with the record tablet with the result that no recordingis obtained. Warning signals have been provided to warn the dictatorunder these circumstances, but such signals are frequently ineffectivebecause of the concentration of the dictator on the subject of thedictation.

The primary object of this invention is to provide a novel and eifectiveback-spacing construction or mechanism, easily adaptable to the abovedescribed type of phonograph or dictating machine, and by which theback-spacing of the recorder-reproducer may be easily and quicklyeffected with'out distractive manipulation on the part of the dictator.

production of the matter recorded within the 10 v back-spaced area hasbeen effected.

A still further object of this invention is to provide a mechanism forthe purposes stated above, which can be controlled from a point remotefrom the phonograph proper. V

Further objects and features of my invention will be d sclosed in thefollowing specification and appended claims.

For a clearer understanding of my invention, attention is directed tothe drawings, accompany- 2o ing and forming part of this specification,wherein:

Figure 1 is a front elevation of a phonograph having a preferredembodiment of my invention applied thereto;

Fig. 2 is a top plan view partly broken away, of the phonograph of Fig.1; I

Fig. 3 is an enlarged side elevational view, partly in section of thecarriage and associated parts of the phonograph of Fig. 1, the recordingand 30 reproducing mechanism being positioned for recording;

Fig. 3A is a further enlarged plan view, partly in section, of themechanism at the rear right comer of the carriage as seen from above;

Fig. 4 is a view of the mechanism of Fig. 3 as seen from below;

Fig. 5 is a fragmental view of the mechanism carried by the carriage inthe position occupied immediately after a back-spacing movement has 40been effected;

Fig. 6 is a sectional view taken substantially on the line 6-6 of Fig.5;

Fig. 7 is a rear elevational view, partly in section, of the carriageshown in Fig. 3;

Fig. 8 is a fragmental view of the rear portion of the carriage takenfrom the left-hand side as seen in Fig. 1;

Fig.9 is a cross sectional view showing in detail the feed wheel of thephonograph of Fig. 1 and its support;

Fig. 10 is an elevational view, partly in section, showing themouthpiece of the dictating machine including the means for remotelycontrolling the pperation of my improved back-spacing mechanism; theelectrical circuit employed to .control said mechanism being shownschematically;

Fig. 11 is a plan view of the mouthpiece of Fig. 10 as seen from above;

Fig. 12 is a section taken on line |2|2 of Fig. 11; and

Fig. 13 isan elevation, partly in section and with parts omitted, of therear portion of the carriage and associated mechanism.

The phonograph is of well known construction and comprises a base 4having upright standards 3, 1 and 1'. A mandrel for supporting a recordtablet A is carried by a shaft 2 joumaled in the standard 3. The mandrelshaft 2 is connected through a suitable clutch 9, I0 to a drive pulley 5which in turn is connected by a belt 8 to a driving motor (not shown). Afeed screw 20, driven from the mandrel shaft by gears 22, 23 is providedfor moving a carriage |3 transversely of the record tablet A. A pair ofguide rods I1, l8 supported by the standards 1, 1' are provided forslidably supporting the carriage I3. Guide rods I1 and I8 are supportedin the standards 1 and 1' so that they are freely rotatable,- but arerestrained against longitudinal movement.

The carriage l3 supports a sound box l4 and control mechanism forshifting the sound box into recording, reproducing or neutral positionby actuation of a control lever 65. The sound box and control mechanismtherefor are of well known construction and are substantially the sameas those described in detail in U. S. Patent to N. H. Holland, No.1,420,316, entitled Phonographs and issued June 20, 1922. The sound boxcomprises a frame 32 having a downwardly extending lug 39 to which ispivotally secured a casing 42 having a sound chamber and a diaphragm 4|.The frame 32 comprises a neck 33 for attachment of an elbow 34 formingthe end of a flexible speaking tube 35. Connection is made between neck33 and the easing 42 by means of a sliding tube 45. The casing 42 isprovided with a tab 42 for coaction with the control mechanism. Astirrup 55 is secured to the diaphragm 4| and carries a recording stylus56. A floating weight 48 positioned below the casing 42 is likewisepivotally secured to the lug 39. The floating weight 48 is provided witha central hole 4| through which the recording stylus 56 and the stirrup55 may pass. An advance ball 80, which may be made of sapphire and whichhas a spherical surface preferably of a radius large in comparison withthe radius of the recording and reproducing styli, is provided on thefloating weight for coaction with the record under certain conditions.The floating weight also carries a reproducing stylus arm 58 pivotallysecured at 60 and carrying a reproducing stylus 59. The end of thestylus arm 58 opposite to that carrying the stylus, lies at all timeswithin the stirrup 55. The floating weight 48 is also provided with atab 48 for coaction with the control mechanism.

The control mechanism comprises a pair of lifting dogs 1| and 12arranged for rotary movement around the guide rod i1. When the controllever is shifted to the forward or recording position (Fig. 3) both ofthe lifting dogs.1| and 12 are moved in a counterclockwise directionuntil they are entirely clear of the tabs 48' and 42' with which theyrespectively coact. Under these conditions the floating weight 48 willmove downwardly until the advance ball 80 contacts the record surfaceand the casing 42 will likewise move downwardly until the recordingstylus 56 is also in contact with the record surface. The advance ball80 contacts the record surface somewhat in advance of the recordingstylus 56 and in consequence, when the mandrel is rotated to cause therecording stylus to cut a phonographic groove in the surface of therecord tablet, the advance ball rides on the uncut portion of the recordtablet in advance of said stylus. If sound waves impinge upon thediaphragm 4|, the depth of the engraving will be varied in accordancetherewith and a phonographic record will be made.

When the control arm 65 is shifted to the neutral position both thelifting dogs 1| and 12 are rotated in a clockwise direction and coactwith their respective tabs 48 and 42' to lift both the floating weight48 and casing 42 and also the styli 56 and 59 entirely clear of therecord.

When the control arm 65 is moved to its rear or reproducing position,the lifting dog 12 remains in its upper position thus holding the casing42 against the frame 32 as in the neutral position. The lifting dog 1|however is then again rotated downwardly or in a counterclockwisedirection and thereby allows the floating weight to move downwardly awayfrom the casing 42. Under these circumstances the rear end of thereproducer stylus arm 58 is held within the stirrup 55 and as a resultthe reproducing stylus arm 58 is rotated in a counterclockwise directionso that the reproducing stylus 59 will engage the record grooves. Whensuch contact occurs, the advance ball is out of contact with the recordsurface and the mass of the floating weight serves to bias thereproducer stylus into its record engaging position. As the mandrel isrotated the stylus is vibrated by the record groove and this vibrationis transmitted by the arm 58 to the stirrup 55 and consequently to thediaphragm 4|, thereby producing sounds corresponding to the engraving onthe record. The mechanism whereby the prescribed motions of the liftingdogs 1| and 12 are attained is described in the above mentioned Hollandpatent and is not therefore described herein. The recording andreproducing mechanism is shown in reproducing position in Fig. 5.

The feeding and back-spacing mechanism, with the exception of the feedscrew 20, is mounted on the rear portion of the carriage |3. Theconstruction of the back-spacing and feeding mechanism is identical withthat described in my copending application Serial No. 375,367, filedJuly 2, 1929. The carriage l3 at its rear end is in the form of a hollowchannel having side walls 90 and 9| and a boss 93. A tube 94 having aninternal diameter of the proper size to receive the rear guide rod I8 isfitted into suitable holes in the boss 93 and in the side wall 9| and issecured against movement therein. The tube 94 extends entirely acrossthe space intervening the side walls of the carriage l3 and forms apivotal mounting for a U-shaped member comprising a rear portion 96 andtwo side arms 4 and H5. The lower portion of the member 96 is bentinwardly (see Fig. 8) to form a mounting bracket 96'. Mounting bracket96' is drilled to receive a threaded portion of a shouldered stud 91which is secured to the bracket by a nut I04. A tubular member 98comprising a Worm gear 99 and having a gear wheel 2| fixed thereto, isrotatably mounted on the stud 91 and is held against longitudinalmovement thereon by a screw ||l| (see Fig. 9). The gear wheel 2| isarranged for engagement with the feed screw 20 and acts under certainconditions as a feed nut. A leaf spring 1 adjustably secured to theside-wall 9| of the carriage coacts with a pin 6 secured in the sidearms 4 and I15 to bias the gear wheel 2| into engagement with the feedscrew 20. The worm gear 89 meshes with a worm I rotatably mounted on thetube 84. By reason of the frictional resistance in the worm and gearconnection, the gear wheel 2| is locked against movement and therebyserves in the same fashion as the more uspal form of feed nut when' thecarriage is being fed across the record by the feed screw. A ratchetwheel III is secured concentrically to the worm I00. Adjacent theratchet wheel I II a cam I is mounted for rotation on the tube 94. Apawl I08 is pivotally mounted on the cam I05 and is biased intoengagement with the ratchet wheel I I I by means of a coil spring H0.The cam I05 carries an inwardly extending pin I06 which passes through ashort circumferential opening I0'I in the tube 94 and into alongitudinal slot I06 in the rear guide rod I8. Adjacent the standard I(see Figs. 1 and 2) the back rod I8 is provided with an arm I24 to theouter end of which a connecting lever I23 is rotatably fastened. Theopposite end of the connecting lever I23 is secured to an armature I22designed to coact with a magnet coil I2I. When the magnet I2I isenergized the armature I22 will be drawn upwardly opposite the core ofthe magnet which will cause a rotary motion to be imparted to the backrod I8. When such rotary motion occurs, the cam I05 will be rotatedbecause of the engagement of pin I06 in slot I06 and the worm I00 willsimultaneously be rotated by reason of the engagement of the pawl I08with the ratchet wheel III. Such rotation of the worm I00 will cause theworm gear 99 and the gear wheel 2| to be rotated and a back-spacingmotion of limited extent is thereby imparted to the carriage, the feedscrew then acting as a rack and the gear wheel 2| as a pinion. When themagnet coil I2I is de-energized, the armature I22 drops down, thusrestoring the cam I05 to its original position. The pawl I08 slides backover the ratchet III, leaving the worm in the position to which it wasmoved during the back-spacing operation. If a back-spacing motion ofgreater extent is desired, the magnet coil I2I may be suc cessivelyenergized and de-energized, thus imparting a step by step back-spacingmotion to the carriage which may be continued to accomplish any desiredextent of backward movement.

The parts of the mechanism thus far described are each separately old inthe art. It will be seen that the mechanism provides manual control forthe positioning of the recording and reproducing mechanism, as well asmeans whereby the carriage may be back-spaced. In order to throw thegear wheel 2| out of engagement with the feed screw 20 when the controllever 65 is moved into the neutral position wherein the carriage I3should be freely movable along the guide rods, a plunger 8| having arounded head 84 is provided for coaction with a roller 84 (see Fig. 3).When the lever 65 is moved to neutral position the roller 84' pushes theplunger 8| backwardly. A push rod 8| secured to the plunger 8| coactswith the upper end of the rear portion 96 of the U-shaped member whichcarries the feed wheel 2| and its associated parts. It will be seen thatwhen the plunger 8| moves backwardly under the influence of the roller84', the portion 96 and consequently the feed wheel 2| will be rotatedin a clockwise direction around therear guide rod I8 and against thetension of the spring I II, thus serving to disengage the gear wheel 2|from the feed nut 20. When the control lever is in either the recordingor reproducing position the spring II'I moves the plunger 8| forward andcauses the gear wheel 2| toengage the feed screw 20.

In order to make the operation of this mechanism automatic it isessential that when a backspacing operation is performed the recorderand reproducer mechanism be simultaneously thrown into reproducingcondition. In order to accomplish this an auxiliary lifting dog I 36having a projecting nose I 31 is pivotally mounted adjacent the liftingclog I2 in such a way that the projecting nose may also coact with thetab 42' on the casing 42 (see Figs. 3, 4 and 5). The lifting dog I36 isfreely rotatable and may be moved independently of the lifting dog 12. Apin I35 is arranged for coaction with a suitable shoulder on the liftingdog I36. The pin I35 is secured to a disk I35 concentric with thelifting dog I36 and is similarly mounted for rotation within a boss I5on the carriage I3. A coil spring I40 connected between the disk I35 andthe outer wall of the boss I5 serves to bias the disc and consequentlythe pin I35 to a point where the nose I31 of the lifting cam I36 isbelow and clear of the lifting tab 42'. A connecting rod I3I ispivotally secured to the pin I35 by a suitably drilled U-shaped memberI34. The connecting rod |3I passes to the rear of the carriage and issupported in a bearing formed in an L-shaped bracket I4I secured to theinner side of wall 90 of the carriage. The rear end of the connectingrod I3I is arranged for coaction with a top portion I30 of a bail havingside arms I28 and I29. The ball is pivoted on one side by a pivot screwI25 passing through the arm I28 and secured in the arm H4, and on theother side by a short shouldered stud I26 passing through the arm I28and secured in the arm II5. A screw I50 threaded in the stud I26 holdsthe arm I29 in place. A coil spring I33 around the pivot screw I25biases the bail toward the rear of the carriage. The arm I28 of the bailis provided with a roller I32 for coaction with the nose of the cam I05. It will therefore be seen that when the back-spacing mechanism isoperated and the cam I05 rotated, a forward motion will be imparted tothe bail which will in turn strike the end of the connecting rod I3I andmove the auxiliary lifting dog I36 in a clockwise direction thus liftingthe casing 42 upwardly and conditioning the recorder-reproducermechanism for reproducing (see Fig. 5).

However as soon as the back-spacing mechanism returns to its normalposition the recorderreproducer mechanism would likewise tend to returnto the recording position. In order to maintain the mechanism inreproducing position, the connecting rod I3I is provided with a notchI3I' for coaction with a latching pawl I42. The pawl I42 is pivoted onthe L-shaped bracket MI by a shoulder screw I43 and is biased intocontact with the connecting rod I3I by a coil spring I44.

As soon as the connecting rod I3I has been moved forward during aback-spacing movement, the latching pawl I42 falls into the notch I3I'and retains the connecting rod I 3| in its forward position and thusmaintains the sound box in its reproducing position.

The latching pawl I42 has a lower extended portion I45 which in normaloperation abuts against a pin I46 carried by a marker plate I41. Themarker plate M1 is supported on the back rod I8 adjacent the carriageI3. It is provided with an enlarged collar I48 carrying a pin I5| forengagement with the slot I06 in the back rod -I8 whereby it ismaintained correctly positioned. It is also provided with a suitablefrictioning device comprising an adjustable spring I49 and a plunger I49housed in a well in the collar I48. When the carriage is in therecording position and is moving forward normally the marker plate ispushed along by the side wall 9| of the carriage. By reason of thecontact between the pin I46 and the lower end I45 of the latching pawl,the marker plate maintains the upper or latching end of the pawl I42completely out of contact with the rod I3I. However, when a back-spacingmotion is imparted to the carriage the marker mechanism is not movedbackwardly with the carriage and as a result the latching pawl is thenfree to fall into the notch I3I and thereby to maintain the recordingand reproducing mechanism in reproducing condition. When all of therecorded matter has been reproduced, the lower end of the latching pawlI42 will again engage the pin I46 and, upon slightly further advance ofthe carriage, will withdraw the latching pawl from the notch I3I andallow the connecting rod I3I to move backwardly under the urging of thecoil spring I40. The casing 42 will thereupon be released and will dropdown until the recording stylus 56 again engages the record andconditions the machine for recording.

In the mechanism just described it will be seen that the recording andreproducing mechanism is returned to recording condition atsubstantially the same point along the record as that at which theback-spacing motion was started. Such an arrangement might result attimes in cutting out a small portion of the groove already recorded ormight shift the recording and reproducing mechanism into recordingposition before the reproduction had been entirely completed. For thisreason it is preferable to allow a slight space to intervene before therecording and reproducing mechanism is again conditioned for recording.In order to accomplish this, the stud I26 on which the arm I29 ispivoted is provided with a camming surface I52 on its outward end. Amember having a complementary camming surface I53 is secured to themarker plate I41 by a screw I50. It will therefore be seen that whenevera back-spacing movement is imparted to the carriage, and the markerplate I41 is rotated upwardly by reason of its pin and slot connectionwith the back rod I8, the marker plate will be cammed to a positionslightly in advance of the farthest point of advance of the carriage.Under these conditions when the carriage again moves up to the markerplate and the recording and reproducing mechanism is again conditionedfor recording by coaction of the marker plate with the pin I46, therewill be a slight gap left between the finish of the previous recordingand the start of the succeeding recording.

The .mechanism above described is available for operation as describedas long as the dictation is continued, providing means for repeating.and subsequently restoring the mechanism to recording conditionwhenever desired. However whenever a cylinder is removed from themandrel and a new cylinder placed thereon it is necessary to move thecontrol lever 65 into the neutral position and to move the entirecarriage backwardly toward the starting position. Under thesecircumstances it is necessary to also retract the marker plate I41 sothat it will always be available in connection with the operation ofrepeating portions of the dictated matter. In order to insure the returnof the marker plate I41 with the carriage, a bracket I69 carrying a pawlI58 pivoted on a screw I59, is secured to the mounting bracket 96'. Whenthe control lever 65 is in recording position the pawl I58 is clear ofthe marker plate I4'I (see Fig. 3) and the relative movement of thecarriage and the' marker plate is not restricted. However, as soon asthe control lever 65 is thrown into neutral position wherein themounting bracket 96 and the feed screw are rotated about the guide rodI8 in a clockwise direction as seen in Fig. 3, the pawl I58 will bemoved inwardly and over the plate I41 as shown in Fig. 3A, so that ifthe carriage is retracted it will serve to carry the marker plate I4'Ialong. As soon as the control lever is again moved in the recordingposition the pawl I58 is again moved out of the way of the marker plate.A spring IIiI serves to bias pawl I58 to the operative position shownand also permits the pawl to ride over the plate M1 in the event saidpawl should be positioned rearwardly thereof by reason of improperoperation of the machine and the carriage should then be advanced, withthe arm 65 set in neutral, for the purpose of restoring said pawl to itsnormal position in advance of plate In the construction shown the feedwheel 2| is held against rotation under normal operating conditions bythe frictional engagement of the worm wheel 99 with the worm I00.However under some circumstances there may be a certain amount ofback-lash or lost motion in the connection of the feed wheel to thecarriage and this is very undesirable during the recording operationwhen it is essential to have the groove engraved upon the record tabletvery accurately. For this reason it may be desirable to provide africtional braking mechanism which will prevent any such lost motion.Such a braking mechanism may comprise a pulley I mounted on the sleeve98 which carries the gear wheel 2|. A brake band I99 is secured at oneend to a pin I92 fixed in bracket 96 andencircles the brake drum I90.The brake band I99 is secured atits other end to another pin I93 fixedin a plate I94 rotatably mounted on the sleeve 98 adjacent the brakedrum I90. The plate I94 has a short extending arm I95 adapted tocooperate with a short arm I95 of a bell crank I9! (see Figs. 4, 7 and8). Bell crank I9? is pivoted on a pin I98 carried by a bracket I99secured to the mounting bracket 96. The long arm of the bell crank isprovided with a short finger 292 adapted to bear against the peripheralsurface 203 of the cam I05. The shape of the cam is such that when themechanism is in normal operating condition a considerable tension ismaintained on the spring band I99 thus preventing any play or lostmotion of the gear wheel 2I. However as soon as a back-spacing motion,is initiated, the cam I05 moves a slight distance and recedes fromfinger 202 to release the tension upon the spring band I90 so that thegear wheel 2I is free to roll along the feed screw and thus cause thebackspacing movement described above.

The speaking tube comprising the flexible tube 35 serves as a soundconduit and is terminated in a mouthpiece 36. The mouthpiece preferablyof moulded insulating material, is provided with a clutch controllingswitch which comprises a switch box I89 and a cover I83 therefor, thecover being pivoted by a screw and bushing I84. The switch cover isnormally biased outwardly and when in this position the clutch isdisengaged. Upon pressing the switch cover I 83 downwardly the clutch isengaged and the mandrel ro- 75 tated. The construction of the clutch andclutch controlling mechanism is of itself no part of this invention andmay be of the type described in Patent No. 1,380,486, to S. G. Langley,dated June 7, 1921, and entitled Controlling device.

In addition to the clutch controlling switch, a second switch isprovided within a casing I10 on the speaking tube for controlling therepeating mechanism described herein. This switch comprises afinger-piece "I of insulating material pivoted in the casing I10 by pinsI12. Fingerpiece I'll carries a metallic connecting arm I11 adapted,when the finger-piece IN is rocked in either direction to make contactand establish a circuit between a pair of double-ended contacts I14,I15, thus establishing a circuit through conductors I20. a battery I20and magnet coil I2I, whereby the repeating mechanism on the phonographis actuated. A coil spring I13 serves to bias the finger-piece "I to itscentral or upright position. It is to be noted that the motion requiredto actuate the repeating control switch is at right angles to thatrequired for the clutch control switch, thus avoiding any confusion asto function. Furthermore closure of the repeating control switch isaccomplished by movement of finger-piece I 1| in either direction sothat succestlve actuations of the back-spacing mechanism may be quicklyeffected by rapid oscillation of the finger-piece. It is intended thatthe finget-piece I" be moved by the index finger which may be donewithout moving the hand from its normal position about the clutchcontrol switch. The operation of the machine is as follows: When it isdesired to dictate, a record tablet A is placed on the mandrel, thecarriage is moved to the beginning of the tablet and the control lever65 moved into recording position. The operator then dictates into themouthpiece, maintaining the switch cover I 83 of the clutch controldepressed as long as'he is speaking into the machine. If during thecourse of the dictation he should be interrupted and upon returningdesire to listen to the last portion of the matter already dictated, orif he should desire to make changes in the matter dictated, or if forany other reason it is necessary that he listen to the Previouslydictated matter, he rocks or oscillates the finger-piece Ill, closingand opening the circuit of the repeat magnet coil [2| one or more times,thus causing any desired number of back-spacing movements of thecarriage as described hereinbefore. During this back-spacing operation,the recording and reproducing mechanism will be conditioned forreproducing and upon completion of the back-spacing motion he may causethe mandrel to rotate by depressing the switch cover I 83, whereupon thecarriage will again move forward and the matter dictated will bereproduced. When the carriage has traveled a slight distance past theend of the dictated matter, the recording and reproducing mechanism willbe automatically restored to the recording condition and he may proceedwith his dictation. The extent of the back-spacing motion depends uponthe number of oscillations given to the fingerpiece "I, one back-spacingoperation being performed for each closure of the switch I11, I14, I15.It isto be understood that if more than one back-spacing operation isperformed, the operations subsequent to the first one will merelyn'esuitin further retraction of thecarriage, the other necessary functionshaving been performed with the first back-spacing operation.

Having thus described my invention, I claim:

1. Ina phonograph, a carriage, a feed screw, carriage advancing meanscomprising a rotatable feed nut mounted on said carriage for coactionwith said feed screw, means to lock said feed nut against playrelatively to said carriage during an advancing movement, back-spacingmechanism for said carriage, said mechanism being adapted to causerotation of said feed nut to cffeet backspacing movement, and meansasso- 1 ciated with said mechanism to render said looking meansinoperative during a back-spacing operation.

2. In a phonograph, a sound box, a feed screw, sound box advancing meanscomprising a gear wheel mounted for coaction with said feed screw,braking means to eliminate play in said feed wheel when it acts as afeed nut during advancing movement of the sound box, sound boxbackspacing mechanism comprising means to rotate said gear wheelwhereupon it coacts with said feed screw as a pinion on a rack to eifectbackspacing, and means associated with said backspacing mechanism forrendering said braking means inoperative during operation of saidbackspacing mechanism.

HEINRICH -F. MAX GRAMANN.

